1. Field of the Invention
This invention relates to an improvement in the field of riveting and more particularly, but not by way of limitation, to an improved tool and arrangement of aiding in the removal of rivets used to secure parts together.
2. Description of the Prior Art
In the field of fastening parts together, riveting is a common and widely used expedient. Although there are many types of rivets used for many different applications a very common type of riveting employs a ductile metal rivet having a head and an extending stem. The stem is inserted into two aligned holes in two parts that have been placed together and the rivet is then upset or squeezed to provide a set rivet which will then securely fasten the parts together. It should be understood that the use of the term "parts" is used in its most broadest generic sense as elements such as a jig may often be considered to be a "part" for the present consideration. While rivets are most commonly used to secure parts together for the foreseeable life of the subassembly and are considered to be hard to remove as opposed to other types of fastening arrangements there are times when it is desired to use riveting as a secure means of fastening and yet remove the rivets either when not properly installed or after a temporal use.
For example, in the art of adhesively bonding together honeycomb sandwich panels or other structures for aerospace applications it is known to use ductile metal rivets to firmly secure the parts to the bond jig so that they do not become inadvertently dislodged during the curing of the assembled parts under pressure and elevated temperature and cause the parts to be scrapped. While riveting provides a sure means of fastening the parts or "tacking" the parts to the bond jig, a significant problem is presented in easily removing the rivets from the bond jig and the attached parts while avoiding damage to either one.
The most common procedure that is presently utilized is for an operator to drill out the center portion of the head of the rivet thereby permitting the stem of the rivet to be knocked out or drilled out. Unfortunately, an operator often has to use a hand held power drill and has trouble drilling through the center of the highly contoured exposed head of the rivet as the drill tends to slip off the rivet head and into cutting engagement with the part or the jig. This is especially true when the rivets to be removed are oriented at ninety degrees to the surface or are at other undesired angles or in hard to reach locations.
One such tool to solve this problem is seen on page 113 of the NASA Tech Briefs dated January/February 1986. This tool comprises a bushing with a base contoured to match a rivet head. The bushing is inserted in a handle which is to be held in one hand by the operator while he simultaneously inserts a power driven drill through the bushing to drill out the rivet. While this tool may be acceptable for removing rivets from flat panels in a laboratory environment it is not acceptable for use in a production environment. In such an environment it would be difficult for the operator to maintain the bushing on the rivet head in an operative manner while simultaneously controlling a power drill, especially in the awkwardly located and oriented locations encountered in production environments. Thus, until the advent of the subject invention a tool has not been available for easily removing set rivets from parts in a production environment. Of interest with respect to the present invention is the art of drill stops for regulating drill depth. For example, U.S. Pat. No. 5,078,552 is directed to a Guide/Drill Stop For Regulating Drill Depth but this type of invention is only concerned with determining drill depth and not with removing set rivets.
None of the prior uncovered art discloses a tool and arrangement for removing set rivets from associated parts and jigs in conventional production environments with a minimum of effort and minimal damage to such parts and jigs.